Re: [PATCH 5/7] perf hists browser: Fix possible memory leak

[Namhyung Kim <namhyung@kernel.org>]

On Mon, Apr 20, 2015 at 10:24:15AM +0200, Jiri Olsa wrote:
> On Sun, Apr 19, 2015 at 01:04:13PM +0900, Namhyung Kim wrote:
> > The options array saves strings for each popup menu item.  The number of
> > items can be vary according to the currently selected item.  So it can
> > leak some memory if it's exited from a small item.  Fix it by freeing
> > all items when loop terminates.
> > 
> > Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> > ---
> >  tools/perf/ui/browsers/hists.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> > diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
> > index 8f303eb5044d..cace2df7e561 100644
> > --- a/tools/perf/ui/browsers/hists.c
> > +++ b/tools/perf/ui/browsers/hists.c
> > @@ -1691,7 +1691,8 @@ skip_annotation:
> >  				"Switch to another data file in PWD") > 0)
> >  			switch_data = nr_options++;
> >  add_exit_option:
> > -		options[nr_options++] = (char *)"Exit";
> > +		if (asprintf(&options[nr_options], "Exit") > 0)
> > +			nr_options++;
> 
> this one could cause segfault right? nice catch

Yes.  But the original code don't cause segfault since it just stops
at 'nr_options - 1'.  When I changed it to go through the whole array,
I found it caused a segfault, so changed it.

Thanks,
Namhyung


> 
> >  retry_popup_menu:
> >  		choice = ui__popup_menu(nr_options, options);
> >  
> > @@ -1812,7 +1813,7 @@ out_free_stack:
> >  	pstack__delete(fstack);
> >  out:
> >  	hist_browser__delete(browser);
> > -	free_popup_options(options, nr_options - 1);
> > +	free_popup_options(options, ARRAY_SIZE(options));
> >  	return key;
> >  }
> >  
> > -- 
> > 2.3.5
> >